In his letter, this NRC staffer alleges that the NRC improperly withheld information about this hazard from the public.

These issues are very grave.

Figure from Google Earth.

Last year’s disaster involving three reactor meltdowns at Fukushima Daiichi was caused in large part by flooding that disabled all the emergency systems needed to cool the reactor cores. The potential hazard at Oconee is all too similar.

Because the NRC is allegedly covering up a nuclear plant hazard, it is imperative that the NRC’s Inspector General promptly investigate this matter and release its findings in a publicly available, un-redacted report.

Here’s a summary of what I’ve been told – from reliable sources – about the matter.

The Oconee nuclear plant is located about 12 miles downstream of the Jocassee Dam (see figure above). Oconee has three pressurized water reactors, each similar to the reactor that melted down at Three Mile Island in 1979. Oconee is the only nuclear power plant in the United States that does not rely on emergency diesel generators to supply electricity to reactor core cooling equipment if the normal source of electricity becomes unavailable. Instead, Oconee gets backup power from the nearby Keowee hydroelectric dam. Backup power from Keowee is supplied to the Standby Shutdown Facility (SSF) housing the equipment needed to cool the reactor cores when the normal power source is lost.

Duke Energy, the plant’s owner, has known since at least 1992 that the 5-foot tall flood wall protecting the SSF is not high enough to prevent equipment inside the SSF from damage if the Jocassee Dam fails. The NRC has known about this situation since at least 1996.

If the Jocassee Dam failed, the three operating reactors could melt within about 10 hours and the containments could fail within 60 hours. In that case, more radiation could be released than escaped following the three reactor meltdowns at Fukushima.

The odds that dams constructed like Jocassee fail have been calculated to be 2.8×10-4 per year, or about 1 in 3,571 chance of failure per year. Oconee is licensed to operate for about another 20 years. The odds of the Jocassee Dam failing over that period are higher than a 1 in 200 chance. These may sound like good odds. But the chance that a tsunami wave higher than its protective seawall would strike Fukushima were reported at around a 1 in 1,000 chance per year. Japan is paying a huge cost for that long shot coming in.

I have also been informed that plans to heighten the protective flood wall at Oconee originally promised to be completed by 2013 have apparently slipped to 2017.

The NRC evaluated this Oconee hazard as well as hazards facing several other nuclear plants from postulated dam failures. The NRC’s evaluation study was reviewed by the Department of Homeland Security (DHS). DHS informed the NRC that nothing in the study needed to be redacted for security reasons. But NRC heavily redacted the report any way before making it publicly available.

The NRC’s Inspector General has to get to the bottom of this matter as quickly as possible. If the Inspector General substantiates the allegations that NRC improperly withheld information from the public, the Congress needs to step in and forcefully remind this agency that such performance will not be tolerated.

NRC must not be allowed to hide bad news and only release the good, fluffy stuff. After all, the NRC isn’t the promotional arm of the nuclear industry. Or at least, it isn’t supposed to be.

Oconee cannot happen in Japan.

Oconee can happen in South Carolina.

It appears that someone needs to intervene to protect the people of South Carolina from Duke Energy and NRC whistling hand-in-hand past the graveyard.

About the author: Mr. Lochbaum received a BS in Nuclear Engineering from the University of Tennessee in 1979 and worked as a nuclear engineer in nuclear power plants for 17 years. In 1992, he and a colleague identified a safety problem in a plant where they were working. When their concerns were ignored by the plant manager, the utility, and the Nuclear Regulatory Commission (NRC), they took the issue to Congress. The problem was eventually corrected at the original plant and at plants across the country. Lochbaum joined UCS in 1996 to work on nuclear power safety. He spent a year in 2009-10 working at the NRC Training Center in Tennessee.
Areas of expertise: Nuclear power safety, nuclear technology and plant design, regulatory oversight, plant license renewal and decommissioning

Support from UCS members make work like this possible. Will you join us? Help UCS advance independent science for a healthy environment and a safer world.

jharragi

When hurricane Irene struck the northeast after last year’s soggy summer, the Moodna Creek had unusual erosion issues where large portions of the bank were undercut and huge amounts of material slumped into the river to be carried downstream by the current. If this type of erosion were to occur upstream of a nuclear facility and be drawn into cooling water systems it could overwhelm screens, pumps or heat exchangers and very rapidly escalate into a disastrous situation The Moodna dumps into the Hudson a few miles upstream of the Indian Point plant. Fortunately that tributary is on the far side of the river so it could not have been an issue at the plant.

The Moodna water was at a flood level that is seen every few years. The erosion that occurred was possibly due to higher saturation of the soils due to higher than average rainfalls in preceding seasons working in concert with the high rainfall. In fact much of the damage in the region was from trees toppling over as their grasp on the soil failed. The lesson from this is that it did not take a cataclysmic flood to create that damage just the right circumstance – and I suppose it could have occurred on a tributary on the east bank instead. In fact there are several reservoirs for the city of Peekskill where those conditions might have initiated dam failure. What might cause an insignificant fluctuation in the level of the Hudson might also bring a huge mud problem.

It is important that studies are conducted to assess these kind of risks. It would be comforting to know that when a risk is identified it is responded to. Hiding that risk might be the appropriate response if you are a plant owner who’s top objective is maximizing profit, but it is a bit disconcerting when the NRC mixes up that owner’s top objective with it’s own of ensuring public safety.